Fluid powered hydraulic motor



Dec. 6, 1966 w DUFFY 3,289,545

FLUID POWERED HYDRAULIC MOTOR Filed Jan. 14, 1966 2 Sheets-Sheet 2 2/lOh IOk lOi FIG.6 FIG.7

INVENTOR- LAWSON W. DUFFY ATTORNEYS United States Patent ()1 3,289,545FLUID POWERED HYDRAULIC MOTOR Lawson W. Duffy, 640 Meadow Ave., SantaClara, Calif. Filed Jan. 14, 1966, Ser. No. 520,681 7 Claims. (Cl.91-273) This invention relates to fluid powered hydraulic motors.

An object of this invention is to provide an improved fluid poweredhydraulic motor that may be easily and economically manufactured bycasting or molding the principal parts thereof out of plastic, metal orthe like.

Another object of this invention is to provide an improved fluid poweredhydraulic motor that may be employed by connecting it to a municipalWater supply in which the water is furnished under considerablepressure, whereby this pressure may be utilized to do useful work afterthe water has reached its destination and the pressure is no longerneeded.

Still another object of this invention is to provide an improvedhydraulic motor which is constructed so that it may be operated withvarious liquids or gases furnished thereto under pressure.

Other and further objects of this invention will be apparent to thoseskilled in the art to which it relates from the following specification,claims and drawing in which, briefly:

FIG. 1 is a longitudinal sectional view of an hydraulic motor of thisinvention;

FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1 showingone of the exhaust valves partially in section and partially broken awayto show part of the exhaust port;

FIG. 3 is a sectional view taken along the line 33 of FIG. 1;

FIG. 4 is a fragmentary sectional view of a modified form of powertakeoff employing a rack and pinion;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 4;

FIG. 6 is a sectional view of another form of power takeofi; and

FIG. 7 is a sectional view taken along the line 77 of FIG. 6.

Referring to the drawing in detail, reference numeral 10 designates themain body or housing of the complete hydraulic motor assembly. The mainbody 10 is made up of two cylinder heads 10a and 10b which are separatedby the gasket 10c and held clamped thereagainst by four bolts 10d. Thecylinder heads 10a and 10b contain the cylindrical working chambers 10eand 10 respectively. The heads 10a and 1012 are also provided withintake ports 11 and 12, respectively, and exhaust ports 13 and 14,respectively, which are concentric with the exhaust ports surroundingthe intake ports.

Valves 15 and 16 are provided for closing the intake ports 11 and 12,respectively, and these valves are springloaded by coil springs 19 and20, respectively, to urge the valves into closed positions. Suitablerecesses are provided in the plugs 17 and 18 for receiving the coilsprings 19 and 20, respectively, and also for receiving the shafts ofthe valves 15 and 16, respectively. Plugs 17 and 18 are threaded intosuitable holes provided in the cylinder heads 10a and 10b, respectively.Cylinder heads 10a and 1011 are also provided with passages 10a and 12a,respectively, connecting the intake ports 11 and 12, respectively, tothe passage 21 which extends longitudinally through these cylinderheads.

End portions of passage 21 are threaded to receive a suitable plug atone end and to receive a suitable coupling at the other end, whereby themotor may be connected to a pipe or hose supplying hydraulic pressurethereto.

Patented Dec. 6, 196:6

Valves 23 and 24, which are fixedly attached to the rigid rod 22, areprovided for closing the exhaust ports 13 and 14, respectively. Springs19 and press valves 15 and 16, respectively, against the pointed ends ofrod 22 which controls the opening and closing of the intake valves 15and 16 during the operation of this device. Rod 22 is provided with aflange 25 fixedly attached to the central part thereof and coil springs27 and 28 are positioned around this rod, one on each side of the flange25.

Pistons 29 and are mounted on the end flanges 26a and 26b, respectively,of tubular member 26. Springs 27 and 28 and the central part of rod 22and the flange 25 are enclosed in this tubular member. Pistons 29 and 30comprise cup-shaped members 2961-291) and 30a-30b. Cup-shaped members29-30a are attached to flange 26a of tubular member 26, and members 30aand 30b are attached to flange 2617. These cup-shaped members may bemade of any suitable material such as rubber, leather, plastic, metal,or the like, and they are assembled back to back so that they are heldagainst the end flanges of the tubular member 26. These cup-shapedmembers may be attached to these flanges by a suitable clamping washersuch as the washer 31 and suitable machine screws such as the machinescrew 32a. Each of the pistons 29 and 30 is made up of two of thesecup-shaped members which have oppositely disposed flanges around thecircumference v thereof in frictional engagement with the inner wall ofis to be driven by this device.

the cylinder cavity.

In each of the cylinder heads 10a and 10b the outer cup-shaped membersof the pistons 29 and 30 have outwardly turned flanges which engage therod 22 and form a seal therewith so that fluid from the correspondingcylinder cavity does not escape along the rod 22 into the tubular member26. A suitable power takeoff member 32 is fixedly attached to thetubular member 26 and extends out of the cylinder heads through suitableslots formed therein. The member 32 is attached to the ends of a U-shaped member 33 which is positioned on the outside of the cylinderheads and which may be connected to any device such as the reciprocatingmember of a mower which The fixed part of the mower may be fixedlyattached to one of the cylinder heads, if

desired. v

The exhaust ports 13 and 14 are connected to passages 13a and 14a,respectively, which are connected to the longitudinally extendingpassage 35 bored through or molded into the cylinders heads 10a and 10b.End portions of the passage 35 may be provided with suitable threads sothat this passage may be connected to a pipe or hose at one end of thedevice and the other end of the passage may be provided with a suitableplug for closing it. The passages 11a, 12a, 13a and 14a also may bebored into the cylinder blocks from the outside thereof and across thepassages 21 and 35, as the case may be, and suitable plugs may bethreaded into the end portions of these passages to seal them from theoutside.

The exhaust valve members 23 and 24 are fixedly attached to the rod 22and these valve members are p0si-. tioned on this rod so that when valvemember 23 is in closed position on exhaust port 13, valve member 24 ismoved away from exhaust port 14. Thus, port 14 is open and at the sametime the end of the rod 22 adjacent to valve member 23 is in engagementwith intake valve 15 and holds this valve in open position so that theintake port 11 is open to the passage 11a and fluid is allowed to flowinto the cylinder chamber 10e through openings 23a provided in valvemember 23. Simultaneously, the end of rod 22 adjacent to the valvemember 24 is withdrawn sufliciently to permit valve 16 to close theintake port 12.

The position of the pistons 29 and 30, shown in FIG. 1, illustrate thesepistons in the extreme left hand positions thereof. At this time theintake valve 16 is closed and the exhaust valve 24 is open so that thefluid from chamber f may be exhausted through the port 14 and passages14a and 35. Also, at this time exhaust valve 23 is closed and intakevalve 15 is open so that fluid pressure from passages 21 and 11a mayenter the intake port 11 and flow through holes 23a in the valve member23 into the chamber 10s. This fluid pressure acts both on the piston 29and on the inner face of exhaust valve member 23. Thus, it holds valvemember 23 closed against the exhaust port 13 and, at the same time,moves the piston 29 to the right. Simultaneously, piston 30 and lever 32are also moved to the right, and spring 27 is compressed while spring 28is relieved. As piston 31) is moved to the right it finally engagesexhaust valve 24 which is fixedly attached to the rod 22, as is alsoexhaust valve 23. Since the effective area of piston 24 is greater thanthe effective area of exhaust valve 23, this exhaust valve is unseatedfrom its closing position on efiaust port 13. At the same time theenergy stored in spring 27, which .is being compressed, actuates rod 22through flange 25 and causes exhaust valve 24 to seat on the exhaustport 14 and also to open intake valve 1 6. Fluid pressure from passages21 and 12a enters intake port 12 and proceeds through holes 24a inexhaust valve 24 into the chamber 10f. This fluid pressure holds exhaustvalve 24 seated on exhaust port 1 4 and also acts against piston 30 tomove the piston assembly to the left in the second half of the cycle ofoperation.

In FIGS. 4, 5, 6 and 7 different forms of power takeoff that may be usedwith this device are shown. A rack 37 is attached to the tubular member26, as shown in FIG. 4, and a pinion gear 38 that is supported on shaft39 meshes with the teeth of rack 37 so that power may be taken off ofshaft 39. Shaft 39 is journaled in member 10g which is in the form of aring inserted between the cylinder heads 10a and 10b between gaskets1011 and 101' which are provided to prevent fluid leakage from passages21 and 35.

The lever 41 is pivotally attached to the member 10k by shaft 42, asshown in FIG. 6. Rollers 43 are provided to the inner ends of lever 41and these rollers are positioned in recesses formed in member 45 whichis fixedly attached to the tubular member 26. Thus, as the member 40 ismoved back and forth during the operation of the device, the outer endof lever 41 is also moved back and forth and may impart this motion to awork load attached thereto.

While I have shown a preferred embodiment of the invention, it will beunderstood that the invention is capable of variation and modificationso that its scope should be limited only by the scope of the claimsappended hereto.

What I claim is:

1. In a hydraulic motor, the combination of a housing having acylindrical cavity therein, piston means slidably positioned in saidcavity, said piston means dividing said cavity into working chambers onopposite sides thereof, each of said working chambers having an intakeport and an exhaust port, intake valve means, a rigid member extendingbetween said intake valve means for controlling said valve means wherebysaid intake ports are opened and closed alternately, exhaust valve meansassociated with said exhaust ports, passages supplying fluid underpressure to said working chambers through the intake ports when theintake valve means thereof is open, passages exhausting fluid from saidworking chamhers through the exhaust ports when the exhaust valve meansthereof is open, each of said exhaust valve means having an area in thecorresponding working chamber exposed to hydraulic pressure in thatworking chamber sufficient to hold the exhaust valve means in thatworking chamber closed when the intake valve means thereof is opened,said exhaust valve means being attached to spaced points on said rigidmember such that when the exhaust valve means of one of said workingchambers is closed, the intake valve means of said one working chamberis opened by said rigid member, resilient means controlled by saidpiston means and acting on said rigid member shifting said rigid memberand the exhaust valve means carried thereby to open the exhaust valvemeans of said one working chamber when the iston means in said oneworking chamber has been moved to expand this chamber to its maximumvolume, said rigid member simultaneously closing the exhaust valve meansin the other of said working chambers and opening intake valve means ofthis latter chamber, and means coupling said piston means to a workload.

'2. In a hydraulic motor, the combination as set forth in claim 1,further comprising means pressing said intake valve means against saidrigid member so that movement of said rigid member controls the openingof one of said intake valve means and the closing of the other of saidintake valve means.

3. In a hydraulic motor, the combination of a housing having acylindrical cavity therein as set forth in claim 2, furthercharacterized in that said piston means comprises two spaced pistonsconnected by a tubular member positioned therebet-ween.

4. In a hydraulic motor, the combination as set forth in claim 3,further characterized in that the intake port and exhaust port of eachof said working chambers are substantially concentric with the exhaustport surrounding the intake port and said rigid member extending throughsaid tubular member.

5. In a hydraulic motor, the combination of a housing having acylindrical cavity therein as set forth in claim 4, furthercharacterized in that said rigid member is provided with a flangeattached thereto, said flange being positioned in said tubular member,said resilient means comprising springs positioned on opposite sides ofsaid flange and engaging said pistons so that one of said springs isbeing compressed and the other is being relieved as said pistons aremoved by hydraulic pressure in said housing.

6. In a hydraulic motor, the combination as set forth in claim 5,further characterized in that said work load coupling means comprises amember attached to said tubular member.

7. In a hydraulic motor, the combination as set forth in claim 6,further characterized in that said work load coupling means comprises apinion gear and said member attached to said tubular member comprises arack having teeth meshing with said pinion gear, and a shaft attached tosaid pinion gear and projecting out of said housing.

References Cited by the Examiner UNITED STATES PATENTS 791,368 5/1905Reynolds 91342 1,355,208 10/1920 Bassler 91342 1,458,383 6/1923 Bassler91342 2,344,802 3/ 1944 Crawford et a1 91-273 2,372,813 4/1945 Darling91273 2,556,698 6/1951 Loewe 91395 2,768,611 10/1956 Anderson 91395MARTIN P. SCHWADRON, Primary Examiner. P. E. MASLOUSKY, AssistantExaminer.

1. IN A HYDRAULIC MOTOR, THE COMBINATION OF A HOUSING HAVING ACYLINDRICAL CAVITY THEREIN, PISTON MEANS SLIDABLY POSITIONED IN SAIDCAVITY, SAID PISTON MEANS DIVIDING SAID CAVITY INTO WORKING CHAMBERS ONOPPOSITE SIDES THEREON, EACH OF SAID WORKING CHAMBERS HAVING AN INTAKEPORT AND AN EXHAUST PORT, INTAKE VALVE MEANS, A RIGID MEMBER EXTENDINGBETWEEN SAID INTAKE VALVE MEANS FOR CONTROLLING SAID VALVE MEANS WHEREBYSAID INTAKE PORTS ARE OPENED AND CLOSED ALTERNATELY, EXHAUST VALVE MEANSASSOCIATED WITH SAID EXHAUST PORTS, PASSAGES SUPPLYING FLUID UNDERPRESSURE TO SAID WORKING CHAMBERS THROUGH THE INTAKE PORTS WHEN THEINTAKE VALVE MEANS THEREOF IS OPEN, PASSAGES EXHAUSTING FLUID FROM SAIDWORKING CHAMBERS THROUGH THE EXHAUST PORTS WHEN THE EXHAUST VALVE MEANSTHEREOF IS OPEN, EACH OF SAID EXHAUST VALVE MEANS HAVING AN AREA IN THECORRESPONDING WORKING CHAMBER EXPOSED TO HYDRAULIC PRESSURE IN THATWORKING CHAMBER SUFFICIENT TO HOLD THE EXHAUST VALVE MEANS IN THATWORKING CHAMBER CLOSED WHEN THE INTAKE VALVE MEANS THEREOF IS OPENED,SAID EXHAUST VALVE MEANS BEING ATTACHED TO SPACED POINTS ON SAID RIGIDMEMBER SUCH THAT WHEN THE EXHAUST VALVE MEANS OF ONE OF SAID WORKINGCHAMBERS IS CLOSED, THE INTAKE VALVE MEANS OF SAID ONE WORKINGCONTROLLED BY SAID PISTON MEANS AND ACTING ON SAID RIDIG MEMBER SHIFTINGSAID RIGID MEMBER AND THE EXHAUST VALVE MEANS CARRIED THEREBY CHAMBERHAS BEEN MOVED TO EXPAND MENT CARRIED THEREBY TO PEN THE EXHAUST VALVEMEANS OF SAID ONE WORKING CHAMBER WHEN THE PISTON MEANS IN SAID ONEWORKING CHAMBER HAS BEEN MOVED TO EXPAND THIS CHAMBER TO ITS MAXIMUMVOLUME, SAID RIGID MEMBER SIMULTANEOUSLY CLOSING THE EXHAUST VALVE MEANSIN THE OTHER OF SAID WORKING CHAMBERS AND OPENING INTAKE VALVE MEANS OFTHIS LATTER CHAMBER, AND MEANS COUPLING SAID PISTON MEANS TO A WORKLOAD.